This is the beginning of a series of threads about how to get a mechanic licence to work on one’s aircraft.
Let’s consider a middle-aged pilot (let’s call him Bob) who desires to get a mechanic licence in order to have the skills and legal possibility to work on his plane, a friend’s plane, or one of his club’s plane. Let’s say all these planes are EASA piston GA planes.
This pilot has a professional activity and can’t work full time on his part66 licence.
Bob must answer the following questions :
- what are the general rules for aviation maintenance licences ?
- which licence category is the most favourable for his situation ?
- what are the possible ways to get this licence ?
As a preamble, this thread will focus on the first 2 questions.
It may seem a little technical but to me it is important to get that answered before we dive in.
All the regs are here
Licence categories :
Category A2 – Piston Engined Aeroplanes
A category A aircraft maintenance licence permits the holder to issue certificates of release to service following minor scheduled line maintenance and simple defect rectification within the limits of tasks specifically endorsed on the certification authorisation given by their Part-145 organization.
Category B1.2 – Piston Engined Aeroplanes
A category B1 aircraft maintenance licence shall permit the holder to issue certificates of release to service and to act as B1 support staff following:
• maintenance performed on aircraft structure, powerplant and mechanical and electrical systems,
• work on avionic systems requiring only simple test
B2 – Avionic
A category B2 aircraft maintenance licence shall permit the holder to issue certificates of release to service and to act as B2 support staff for following:
• maintenance performed on avionic and electrical systems, and
• electrical and avionics tasks within powerplant and mechanical systems, requiring only simple test
A B3 licence is like a B1 but restricted piston engine non-pressurized aircraft below 2,000kg mass
Category C
The category C licence permits certification of scheduled base maintenance by the issue of a single certificate of release to service for the complete aircraft after the completion of all such maintenance. The basis for this certification is that the maintenance has been carried out by competent mechanics, and category B1, B2, B2L, B3 and L support staff, as appropriate, have signed for the maintenance tasks under their respective specialisation.
As you can see, categories A and C don’t fit with Bob’s requirements. That leaves :
• B1.2
• B2
• B3
There are 2 ways to get an Aviation Maintenance License (AML)
- grand father rights
- passing tests and meeting experience requirements.
Requirements are twofold. Some all general to all AML and some are specific.
Here are some noteworthy general requirements :
Definition of experience :
Maintenance experience on operating aircraft:
• means the experience of being involved in maintenance tasks on aircraft which are being operated by airlines, air taxi organisations, aero clubs, owners, etc., as relevant to the licence category/subcategory;
• should cover a wide range of tasks in terms of length, complexity and variety;
• may be gained within different types of maintenance organisations (Part-145, M.A. Subpart F, Part-CAO, FAR-145, etc.) or under the supervision of independent certifying staff;
• May be combined with Part-147 approved training (or other training approved by the competent authority) so that periods of training can be intermixed with periods of experience, similar to an apprenticeship;
• may be full-time or part-time, either as professional or on a voluntary basis;
Recent initial experience :
At least 1 year of the required experience shall be recent maintenance experience on aircraft of the category/subcategory for which the initial aircraft maintenance licence is sought. To be considered as recent experience; at least 50% of the required 12-month recent experience should be gained within the 12 month period prior to the date of application for the aircraft maintenance licence. The remainder of the recent experience should have been gained within the 7-year period prior to application. It must be noted that the rest of the basic experience required by 66.A.30 must be obtained within the 10 years prior to the application.
Recurring recent experience :
The holder of an aircraft maintenance licence may not exercise its privileges unless in the preceding 2-year period he/she has, either had 6 months (100 days) of maintenance experience in accordance with the privileges granted by the aircraft maintenance licence or, met the provision for the issue of the appropriate privileges. The holder should show experience on at least one aircraft type per aircraft structure (metal, composite, wood).
Experience and training validity :
The training courses and examinations shall have been passed within 10 years prior to the application for an aircraft maintenance licence. Experience shall have been acquired within the 10 years preceding the application for an aircraft maintenance licence.
License validity :
The aircraft maintenance licence becomes invalid 5 years after its last issue or change
Specific requirements
Experience requirement for B1.2 and B3:
Experience requirement for category B2 :
Explanation :
No previous relevant technical training = you work on planes and take the tests by yourself
A skilled worker is a person who has successfully completed a training, acceptable to the competent authority, involving the manufacture, repair, overhaul or inspection of mechanical, electrical or electronic equipment. The training would include the use of tools and measuring devices.
Category B1 and B3, unless the applicant provides evidence of appropriate experience, shall be subject to the following limitations, which shall be endorsed on the licence:
• pressurised aeroplanes,
• metal-structure aeroplanes,
• composite-structure aeroplanes,
• wooden-structure aeroplanes,
• aeroplanes with metal-tubing structure covered with fabric;
So you can have a licence restricted to one or several types of airframes
Finally, about grand father rights, the reg contains this interesting exception :
Where a pilot-owner holds a pre-Part-66 qualification which covered privileges to release work performed on aircraft structures, powerplant, mechanical and electrical systems but limited to their own aircraft and limited to a particular aircraft type (for example, a Cessna 172). This pilot-owner would receive a Part-66 aircraft maintenance licence in the B1.2 or B3 (sub)category with the following limitations (exclusions):
• aircraft used by air carriers licensed in accordance with Regulation (EC) No 1008/2008 (this limitation always exists);
• aircraft other than a Cessna 172;
• aircraft not owned by the licence holder.
My conclusion at first sight:
The good news is your time spent on your plane with any mechanic counts.
The bad news is an AML is perishable. You must work at least 50 days a year to keep it valid. I don’t get the conditions for the 5-year renewal. Demonstrating 6 months of recent experience is enough ?
Interesting, thanks for compiling this information.
However, what exactly can one do to obtain a Part 66 license (part time)? Is there any organization for training towards it out there?
You’re welcome.
That will be the subject of another thread.
This one I wanted to inform people and launch a discussion about :
Interesting indeed,
Will you cover Part-66 L2?
As a pilot who gained a B1.2 + B2 in my free time, I am happy to share my experience.
First and foremost, there seems to be less uniformity in the application of the Part-66 regulations across different EASA member states than Part-FCL: national CAAs may have their own ways of judging what kind of maintenance experience is acceptable and what isn’t. Some countries (e.g. the Netherlands) even delegate the issuance of Part-66 licences to an independent organisation. Here in Czechia, the CAA wanted four things:
1. Examination certificate: in the past, they would accept modules 1 and 2 automatically, without examinations, on the basis of a high school diploma stating one had studied mathematics and physics, and possibly module 3 on the basis of a higher education diploma in a relevant technical field. However, in 2019 they were audited by EASA, which said this information was not properly verifiable, so from then on all the applicants had to take examinations in modules 1, 2 and 3 as well. These are trivial, but I had to go back to the Part-147 MTO and take them. Generally, CAA expects to see all the modules on one certificate, but in this case they accepted two (issued by the same MTO).
2. Certificates of B1+B2 type training for two types. I had them, but they could otherwise be substituted by letters from maintenance organisation that I performed a full annual inspection on such and such type under supervision.
3. Evidence of Practical Experience appendix to Form 19 with a list of maintenance tasks. Out of that standard list, one has to perform at least 50% of the tasks applicable to the categories applied for. Instructor signatures for individual tasks did not have to be from the actual instructor supervising me, it could be an accountable manager or quality manager of the maintenance organisation. I also wrote in a few tasks that were clearly relevant but not included in the standard list.
4. Letters from all maintenance organisations I worked at (there were three) stating that I worked there from such and such date until such and such date, performing maintenance on such and such aircraft under, and that my work covered a ‘representative cross section’ (it’s a standard expression from the regulations) of the relevant tasks and was favourably assessed by the certifying staff.
Two of the three organisations that issued my letters and signed off the list of tasks were local, the third one was in the UK (before Brexit). They weren’t totally happy with that one, but I also submitted a proof of ownership of a G-reg aircraft and a letter of authorisation from my UK CAMO allowing me to perform maintenance up to 50-hour inspection inclusive. This convinced them.
Ultranomad wrote:
Examination certificate: in the past, they would accept modules 1 and 2 automatically, without examinations, on the basis of a high school diploma stating one had studied mathematics and physics, and possibly module 3 on the basis of a higher education diploma in a relevant technical field. However, in 2019 they were audited by EASA, which said this information was not properly verifiable, so from then on all the applicants had to take examinations in modules 1, 2 and 3 as well. These are trivial, but I had to go back to the Part-147 MTO and take them. Generally, CAA expects to see all the modules on one certificate, but in this case they accepted two (issued by the same MTO).
In UK, one can take Part66 theory exams on freelance without approved course (I did half of them by self-study plus math/physics)
For practical experience, one can get this reduced by doing approved 147 course or 145 organization, I struggled to find one single place that can ‘give me work’ even for free, other than SEP/TMG in Gliding Club where I managed to get few task signed and actually learn something 
I gave up on this, I may try again when I am 80 years old in gliding or aero-club without kid, license, medical…although, honestly, I will be fiddling with ULMs, Gyros and Homebuilts
I admire anyone like you who had gone though this !
Benjamone wrote:
Will you cover Part-66 L2?
Crap, totally missed this one. Thank you very much !
The L2 subcategory includes all powered sailplanes and ELA1 aeroplanes (composite, metal and wood).
I missed B2L too, which is basically a B2 limited to GA.
So
Sorry it was late, I was in a rush to finish my post. It’s more complex than I thought !
I will update when I have time.
Ibra wrote:
In UK, one can take Part66 theory exams on freelance without approved course (I did half of them by self-study plus math/physics)
Same in the EU – the Part-147 MTO I mentioned was only administering exams and offering consultations to those who wanted them, not a full-fledged course.
If you have an engineering or physics background, most modules are really easy. Some questions were familiar to me since early childhood from the stories my mechanical engineer grandfather was telling me while walking with me in the park.
Some questions were familiar to me since early childhood from the stories my mechanical engineer grandfather was telling me while walking with me in the park.
Preparing these exams decades ago 
I saw some of the questions in the “electrical” papers, shown to me by two FAA mechanics training towards Part 66 here, approx 15 years ago and 10 years ago.
The questions were seriously badly written and the answers were mostly BS. Hard to believe this sort of garbage was being taught; the system obviously hangs together only because the subject matter is never used. But it is no surprise that probably 99% of mechanics here can use a spanner but cannot troubleshoot an alternator. The result is incredible stories like that guy in the UK with a diesel Robin which wouldn’t start, and every part in the chain (starter motor, starter relay, the whole damned lot) were gradually replaced!! Multimeter, anyone??
But a lot of aviation theory works like this. The PPL theory is also mostly garbage, the ATPL (CPL/IR) likewise, but these hang together because the particular material is not actually used. The whole aviation theory system is one giant BS-treadmill, designed by people who never flew (or repaired) a kite, and whose primary job is to keep the entry into the profession relatively hard.
Good luck @Jujupilote in your quest. But you won’t need it; you will find it laughably easy
